EUVD-2026-59551
GHSA-grxx-h4mr-vfpg
Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
AC:H because the overflow requires 255+ IOMEM reserved memory regions, a hardware-firmware condition outside direct attacker control.
Primary rating from Vendor (Linux).
CVSS VectorVendor: Linux
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
5DescriptionCVE.org
In the Linux kernel, the following vulnerability has been resolved:
crypto: ccp - Fix snp_filter_reserved_mem_regions() off-by-one
Sashiko notes:
> regarding the bounds check in snp_filter_reserved_mem_regions() > called via walk_iomem_res_desc(): does the check > if ((range_list->num_elements * 16 + 8) > PAGE_SIZE) > allow an off-by-one heap buffer overflow? > > If range_list->num_elements is 255, 255 * 16 + 8 = 4088, which is <= 4096. > Writing range->base (8 bytes) fills 4088-4095, but writing range->page_count > (4 bytes) would write to 4096-4099, overflowing the kzalloc-allocated > PAGE_SIZE buffer.
Fix this by accounting for the entry about to be written to, in addition to the entries that are already allocated.
AnalysisAI
Heap buffer overflow in the Linux kernel CCP driver's snp_filter_reserved_mem_regions() function enables a low-privileged local attacker to corrupt kernel memory on AMD SEV-SNP-enabled systems. The off-by-one error in the boundary check permits a 4-byte write past a PAGE_SIZE kzalloc buffer when 255 or more IOMEM reserved memory regions are present, yielding full High impact on confidentiality, integrity, and availability per CVSS 7.8. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Exploitation requires a low-privileged local account on the target system (PR:L per the provided CVSS:3.1/AV:L vector - remote exploitation is not possible). … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | The CVSS 7.8 High rating (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) reflects local privilege escalation potential with full impact across confidentiality, integrity, and availability. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | A local attacker with a low-privileged account on an AMD EPYC server with SEV-SNP enabled invokes the CCP driver's memory region enumeration path on a system whose firmware reports 255 or more IOMEM reserved regions, causing the deficient boundary check to pass. The subsequent 4-byte write to range->page_count lands in adjacent heap memory, corrupting a neighboring kernel allocation; with knowledge of kernel heap layout, the attacker shapes the heap to place a security-sensitive structure adjacent to the overflow target and leverages the corruption to escalate to kernel-level code execution. … |
| Remediation | Upgrade to a patched Linux kernel stable release: version 6.12.97, 6.18.40, or 7.1.5, or any build incorporating the fix commits at https://git.kernel.org/stable/c/830c1f3e71989448652973375ef5e39b6ede47a3 and the equivalent backports at c5c79d92da0f9a09f48be5e2aabed2d6d1a96294, af7341616b742ad2c374a90998bd650a035f694d, and 1b864b6cb213bbd7b406e9b2e98c962077f300df. … Detailed patch versions, workarounds, and compensating controls in full report. |
Recommended ActionAI
Within 24 hours, identify all systems in your environment running the Linux kernel on AMD SEV-SNP-enabled hardware and assess whether SEV-SNP is active; contact your hardware or cloud provider for confirmation if unclear. …
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Same technique Buffer Overflow
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